The present embodiments relate generally to an electrical connector and, more particularly, to protecting pins in an electrical connector from incorrectly having injection potential applied.
An electrical connector is a device which allows circuits to be joined. When used in commercial airplanes, an electrical connector joins the circuitry in a controller to an aircraft wiring harness. Circuitry in the controller can include, for example, discrete inputs and outputs, microprocessor boards, analog interface boards, and communications devices. The aircraft wiring harness connects the circuitry in the controller to other devices such as linear variable differential transformer (LVDT) based sensors, resolver based sensors, status lights, and communication buses. Some of the circuitry in the controller interfaces with sensors that are exposed to the outside world, such as sensors on the wings.
Because some of the circuitry in the controller interfaces with devices exposed to the outside world, it is required that such controller circuitry be tested to ensure it is able to withstand a lightning strike. Therefore, pin injection testing is used to simulate a lightning strike by applying high potential only to those pins in the electrical connector coupled to circuitry which interfaces with devices that could experience a lightning strike. This pin injection testing verifies whether the controller can withstand the requisite high potential applied. However, an electrical connector has many pins within it which couple to various circuitry, and only some of those pins couple to circuitry which interfaces with devices exposed to the outside world. Thus, during pin injection testing only some of the pins in the electrical connector are to have the high potential applied to them, whereas other pins are not to have potential applied to them. If potential is applied to an incorrect pin during pin injection testing, the controller may be damaged, possibly resulting in tens of thousands of dollars in damage and the inability to use the controller in further testing.
When electrical connectors are shipped, a plate may be installed over each block of the electrical connector to prevent damage. Such a plate may also be installed to cover an entire block of pins in an electrical connector to prevent potential from being applied to an incorrect pin. Installing the plate prevents injection potential from being applied to an incorrect pin within that block; however, this type of plate also prevents pins which are to be tested from being accessible. Therefore, to test an identified pin within the block, the plate must be removed, once again exposing pins that are not to be tested. Furthermore, when the plate is removed, there is no way to distinguish pins which are to have potential applied from those that are not to have potential applied without manually counting the pins to identify the pin number. This introduces the possibility of human error if the pins are not counted correctly.